Hammer-drill.



liti

" drill type, provided with MSSACHUSETIS.

Specification of Letters Patent.

HAMMER-DRILL.

Patented Uct. 9, 1917.

Application filed March 2, 1915. Serial No. 11,561.

To all w/wm it may concern.'

Be it known that I, GEORGE H. GILMAN, a citizen of the United States, and a resident oit Claremont, county of Sullivan, and citate of New Hampshire, have invented an Improvement in Hammer-Drills, of which the following description, in connection with the accompanying drawings, is a specification, likecharacters on the drawings repre'- senting like parts.

This invention'relates to hammer drills and more particularly to hammer drills of the selirot-a ting type. The object is to provide means to prevent the entrance of dirt or grit into the chuck bearing and the internal working parts of a self-rotating hammer drill when it is used for drilling vertical er approximately vertical holes.

he invention will be best understood from the following description when taken in connection with the accompanying illustration of one specific embodiment thereof,

while its scope will be more particularly pointed out in the appended claims.

ln the drawings z Figure 1 is a side elevation of a pressure fed stoping hammer drill embodying one form of the invention; and

Fig2 is a sectional elevation showing, on an enlarged scale, the construction of the front head of such drill.

' Referring to the drawings and to the embodiment of the invention therein shown, the stoping tool is of the percussive hammer a cylinder 1, secured to the head block 2, the latter conneeted to the pneumatic tee'd cylinder 3. The 'feed cylinder 'is provided with a feed piston 4, connected to the piston rod 5, provided with a projecting pointed end 6, whereby, as is common with devices oit' ,this class, the tool, after being set in position, may be fed toward its work by the admission of pressurev fluid from a suitable source (not shown) to the feed cylinder. The latter is under the control. of a main controlling valve, the handle for which is shown at i', such controlling valve serving also to control the throttle for the tool. The cylinder 1 is provided with a cylinder head 8 and overlaps the front head 10, and the front head, cylinder, head block and'ieed cylinder are all securely clamped together by means of the side rods 11 passing yrearwardly through flanges 12 in" the tront head and able means as by secured at their opposite ends to a yoke 13, the latter being seated upon the front end of the fe'ed cylinder at the rear block. y

Referring now to the construction of the front head and the parts connected there with :for rotating the drill steel, the chuck for receiving the latter is rotatably mounted in the front head 10, and has a forward portion 14 projecting from the front head. Such a forward portion has a bore adapted to receive the drill-receiving bushing 15, and is split along the line 16 whereby the bushing 15, after insertion, may be clamped tightly in position by means oi.E the clamping bolt 17 carried by the lugs 1S formed on the projecting portion .11 ot' the chuck. The bushing has a bore preferably of a hexagonal orother non-circula r cross section suitable to receive the end o't` the drill bit and hold the same non-rotatable in the chuck.

The drill steel (indicated in dotted lines in Fig. 2) when inserted in the chuck is seated against the front lace of a tappet or anvil block 20, the latter consisting of a portion of larger diameter arranged in the larger bore'oiI the chuck member, and a shank 21 of `smaller diameter projecting rearwardly through a chuck ot smaller bore diameter, whereby there is provided a shoulder 22 on the block seated against a shoulder in the chuck and whereby the smaller portion of the anvil block projects back into the path ofthe piston hummer extension 23, and is adapted to receive the impact thereol and transmit the same to the drill steel. v l The hammer extension 23 is rigidly secured to andprojects forwardly from the pistonv hammer 24r through. a bore in the cylinder head 8'. The piston is arranged to vreciprocate in the cylinder 1 as is usual in l this class of devices, and any usual or ordinary controlling valve (not shown) may be used.

The portion of the chuck which is rotatably mounted within the cylinder head includes the rearward anvil-carrying portion 25, the rear end of which bears against the front face of the shoi'ildered portion 26 in the front head, and a rearward extension 27, the latter in the form of a chuck sleeve secured to the chuck portion by any suitthreaded v engagement of the head therewith, and having an internal bore of suitable diameter to .'slii'lably` fit thc hammer extension The rearward extension 27, or sleeve, is provided with a flange or enlarged shoulder 2S, the forward face of which abut's against and engages with the rearward face el the shoulder lll 'on the front head. By thisl means. the chuck is not only rotatably mounted within the front head, but is retained therein, and its longitudinal displacement prevented.

To rotate the chuck suitable means are provided for turning the piston and the hammer extension step-by-step, such rotative step-by-step movement being communicated to the chuck by means oli' the fixed in the rearward extension 2T ot' the chuck, said keys being slidably engaged by straight grooves 30 in the hammer bar extension.

Any suitable means may be emgloyed for imparting a step-hy-step rotative movement to the piston, but herein l have'shown devices which are substantially the same as those shown in my prior latent No. 1,034,010, to which reference may be had Jfor fuller details. Such rotative mechanism embodies a ratchet member 3l having interior helical keys or teeth (not shown) slidably engaged with heli-al grooves 32 formed in the piston extension, said ratchet being `freely rotatable in one direction, but locked against movement in the opposite direction by suitable clutching devices. herein shown in the form ot rollers l2-i, engaging the teeth et' the ratchet and pressed against the same by the springs 34.

In order to prevent the entrance of dust or grit into the bearing parts of' the chuck and the internal working parts of the drill, the forward or projecting portion 14 thereof is provided with means which overlap and protect the joint between the front head and the chuck. While such protection might be embodied in the form of a separate attachment, herein it is provided by enlarging the diameter of the projecting portion lil so that the latter is in theform of a nose-piece provided with a flange 35 overlapping the Vforward end ol? the front head and protecting the joint thereat from the entrance of dust or grit. Preferably passages 36 are provided which extend at an inclination rearwardly from the chuck projecting portion l-l so as to connect the space at the liront ol'A the anvil block with the open air and thereby permit the escape ot any dust or gril', which accumulates in or enters the said space.

l/Vhile l. have herein shown and described for purposes oli illustration one specil'ic. form of my invention, it is to be understood that extensive deviations may hc. made from the construction herein disclosed without departing from the spirit of the. invention, and

'that it may that not only is t e same capable of embodiment in a great variety of forms, but be applied to tools of widely different construction from that herein shown.

Claims:

l. In a fluid operated percussive drill, a cylinder having a flange on its front end, a trent head seated within said flange, and a. two-part rotatable drill chuck seated in lsaid head' and interlocked therewith having a portion overlapping the frontend thereof.

'2. In a fluid operated percussive drill, a cylinder having a flange on its forward end, a front head seated in said lange and overlapped thereby, a two-part rotatable drill chuck seated in said head and having a portion overlapping the front end thereof and a portion threaded thereto cooperating therewith in interlocking said head and chuck against longitudinal movement.

3. ln a fluid operated percussive drill, a cylinder, a front head seated therein having an internal annular flange at a point intermediate ts ends, and a two part drill chuck seated in said head having a portion overlapping the frontend ot' said head and a cooperating flanged portion engaging the rear wall ot' the fiange on said head.

l. lu a. fluid ope 'ated percussive drill, a cylinder, a front head seated thereon having au internal annular flange, and a drill chuck seated in said head comprising a pair of connected sections, one having a portion engaging the t'ront wall of said Bange and the 100 other having a flange portion engaging the rear wall ot the flange on said front head.

5. ln a fluid operated percussive drlll, a

l cylinder, a front head seated thereon having an internal annular flange, and a drill chuck 105 sated in said head comprising a plurality ot' sections threaded together at their opposite ends and one having a portion engagmg the front wall of said flange and the other having a flange engaging the rear Wall of said flange.

6. In a fluid operated perci'issive drill, a, cylinder, a front head seated on said cylinder, said trout head having an internal projection thereon, a drill chuck disposed Within said head and having its rear wall in engagement with the front wall of said projection, and a coperatiug drill chuck member removably attached to said chuck having a flange thereon engageable with the rear Wall ol5 said projection.

7. ln a fluid ope-ated pcrcussive drill, a cylinder, ay cylinder head therein, a piston movable through said head, rotative mecha nism in said cylinder beyoiul the front end ot' said head, a trent head in said cylinder having an internal annular flange, a flanged ehuck member engaging the rear Wall of said flange and cope ating with said cylinder head'to confine said rotative mechanism, 130

ieeeeee mixing chuck me'mher thi'eeded tlielete he ig a portion engageelole with the opposite Wall of seid flange.

8. ln a Huid operated percuesive drill, ai eylindei', a, front heed seated in the if'i'oiit end thereof and eveilepped thereby having an internal annule? flange intermediate its ends, a drill chuck member rotatably mouI1t-\ ed in seidhead having its real' end of iheleesed internal diameter and extending to e point adjacent the iii-ent Well 0I said flange, and e coperating; chuck member threaded Within the rear end of said irst mentioned member end having en annuler flange on its rem end engaging the reel' Well of the flange on said front head.

9. ln e fluid operated permissive drill, cylinder, e cylinder heed therein, e pieten l'ieving e reduced end movable through Said head, iotativ'e meclmiliem in said cylinder in front of the :iont end et seid heed and opeiatively connected to Said piston; a front head seated in the liront end of seid eylindee, and a drill chucli operatively connected to seid piston inteilocked with said from head against longitudinal movement :md coper ating with the latter to confine said rotative mechanism.

10. ln ii fluid operated peieuee`ve drill, e cylinder, e cylinder heed therein, e mnt head seated in seid e'ulf'linde, e pieten hevieg e, luted hammer extensieiii movable through eid eylliider heed, rotative meehe- 'oliride e e lieder head therein miem including' a ratchet eopereting with said luted extension and disposed between said cylinder head and front head, en inteln Anelly liuted chuck membei Seated iii seid front head end copeifating with seid eyliiin der head to eonline eaidrzitchet, and ehiiel: member coperetiiig therewith in leeliziiig Seid Chuck egailet longitudinal mevetrieilta ll. in a, duid operated permissive diiih e head seated in, said cylindei eveilepped thereby, having an internal zielige thereon, e piston having e iiuted hammer extei'lsien movable through seid cylinder heed5 :when4 tive mechanism including e ratchet eelpeiating with said uted extension aiid die posed edjeeenteeid cylinder head, an internally uted cliiieli memhei seated iii seid front head and eving a flange engaging; the ange thereon i d copel'atihg with seid eylinfiel' heed to mme Seid ratchet7 ande eo operating che@ member attached te seid chuck memheihd likewise engaging the flange on said i'eht head having en enlarged front portion ei/eilepping the` foiweid of said front h In testimony l ereeii, lieve sighedmy name to this speeiiieetien, in the pi'eeeiiee of two .subscribing 'iui'tneeeee 

